Tl0.33TaSe2
hP4
(187) P-6m2 – hba
Tl0.33TaSe2 [1]; InNbS2 [2]; In0.5NbSe2 [4]; In0.67TaS2 [3]; Tl0.5TaS2 [5]
Structural features: Directly superposed close-packed Se layers; Ta and Tl in trigonal prismatic voids
(stacking sequence AbAβ). TaSe6 trigonal prisms share edges to form infinite slabs; Tl in trigonal
prismatic voids between the slabs. Ignoring vacancies, substitution derivative of WC.
Müller D. et al. (1974) [1]
Se2TaTl0.33
a = 0.3473, c = 0.8353 nm, c/a = 2.405, V = 0.0873 nm3, Z = 1
site
Wyck. sym.
x
y
z
occ.
atomic environment
__________________________________________________________________________________________________________________________________________________________________________
Se1
Tl2
Ta3
2h
1b
1a
3m.
-6m2
-6m2
1
/3
0
0
2
/3
0
0
0.1981
/2
0
1
non-coplanar triangle Ta3
0.328 anticuboctahedron Se6Tl6
trigonal prism Se6
__________________________________________________________________________________________________________________________________________________________________________
Transformation from published data: -x,-y,-z
Experimental: single crystal, Weissenberg photographs, X-rays, R = 0.074
Remarks: Refinement of the site occupancies showed no significant deviation from unity except for site
Tl2.
References: [1] Müller D., Poltmann F.E., Hahn H. (1974), Z. Anorg. Allg. Chem. 410, 129-137. [2]
Eppinga R., Wiegers G.A. (1980), Physica B+C (Amsterdam) 99, 121-127. [3] Di Salvo F.J., Hull G.W.
Jr., Schwartz L.H., Voorhoeve J.M., Waszczak J.V. (1973), J. Chem. Phys. 59, 1922-1929. [4] Kulikov
L.M., Romaka L.P., Aksel'rud L.G., Semenov Kobzar A.A. (1989), Vses. Konf. Kristallokhim. Intermet.
Soeden., 5th, L'vov 1989, Coll. Abstr. p. 29. [5] Schmidt V. (1971), thesis, Tübingen U., Germany.
Landolt-Börnstein
New Series III/43A4